Opportunities for Gene and Environment Research in Cancer: An Updated Review of NCI's Extramural Grant Portfolio

Abstract

Background: The study of gene-environment (GxE) interactions is a research priority for the NCI. Previously, our group analyzed NCI's extramural grant portfolio from fiscal years (FY) 2007 to 2009 to determine the state of the science in GxE research. This study builds upon our previous effort and examines changes in the landscape of GxE cancer research funded by NCI.

Methods: The NCI grant portfolio was examined from FY 2010 to 2018 using the iSearch application. A time-trend analysis was conducted to explore changes over the study interval.

Results: A total of 107 grants met the search criteria and were abstracted. The most common cancer types studied were breast (19.6%) and colorectal (18.7%). Most grants focused on GxE using specific candidate genes (69.2%) compared with agnostic approaches using genome-wide (26.2%) or whole-exome/whole-genome next-generation sequencing (NGS) approaches (19.6%); some grants used more than one approach to assess genetic variation. More funded grants incorporated NGS technologies in FY 2016-2018 compared with prior FYs. Environmental exposures most commonly examined were energy balance (46.7%) and drugs/treatment (40.2%). Over the time interval, we observed a decrease in energy balance applications with a concurrent increase in drug/treatment applications.

Conclusions: Research in GxE interactions has continued to concentrate on common cancers, while there have been some shifts in focus of genetic and environmental exposures. Opportunities exist to study less common cancers, apply new technologies, and increase racial/ethnic diversity.

Impact: This analysis of NCI's extramural grant portfolio updates previous efforts and provides a review of NCI grant support for GxE research.

Figure 1.

Flow diagram of search strategy and review process of the National Cancer Institute’s extramural grant portfolio on gene-environment interaction research, fiscal years 2010–2018. Flow diagram of portfolio analysis search strategy and review process.

Figure 2.

Distribution of the cancer types examined among the 107 relevant gene-environment interaction grants funded by the National Cancer Institute, fiscal years 2010–2018. Number of cancer types and categories captured in portfolio analysis. The bars are labeled with the total number of grants that investigated each cancer type. The total number of grants is 107; however, some grants investigated more than one cancer type and were counted more than once in the total for this specific figure.

Figure 3.

Distribution among the most common environmental exposure categories examined among the 107 relevant gene-environment interaction grants funded by the National Cancer Institute, fiscal years 2010–2018. Number of environmental exposures captured in portfolio analysis. Environmental exposure categories used in this portfolio analysis are listed and the bars are labeled with the total number of grants that investigated each environmental exposure category. The total number of grants is 107; however, some grants investigated more than one environmental exposure and were counted more than once in the total for this specific figure.